JP2003172934A - Homeotropic liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that an alignment of a liquid crystal near an alignment control means has a dispersion which divides the alignment of the liquid crystal for each pixel in a homeotropic liquid crystal display device. <P>SOLUTION: The homeotropic liquid crystal display device has the liquid crystal which has a negative anisotropic permittivity, and a vertical alignment film which aligns the liquid crystal vertically in an initial alignment state where voltage is not applied, and has the alignment control means formed corresponding to each pixel electrode. The alignment control means consists of a portion extended long which is extended to column direction and a portion extended short which forms a prescribed angle with the portion extended long, and which is extended from an end of the portion extended long. Each end of the portion extended long eliminates a portion which the alignment control means branches by having one portion extended short. Dispersion in the direction of the alignment of the liquid crystal which is originated under an effect of an electric field of two directions generated in the portion to branch, and an optical leakage resulting from it are cancelled. The aperture ratio is improved, because the area of the alignment control means can be reduced. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical alignment type liquid crystal display device.

[0002]

2. Description of the Related Art Some vertical alignment type liquid crystal display devices have an alignment control means for dividing the alignment direction of the liquid crystal in a pixel electrode for driving the liquid crystal. The alignment control means is provided with an alignment control window formed by opening a counter electrode facing the pixel electrode and driving liquid crystal together with the pixel electrode, and at least a ridge on the pixel electrode or the counter electrode. There is an alignment control inclined part formed by the above, and a combination of the alignment control window and the alignment control inclined part, for example, JP-A-12-2144.
It is disclosed in Japanese Patent No. 64 and Japanese Patent No. 3005418. These orientation control means divide the orientation direction of the liquid crystal in each pixel electrode by dividing the electric field formed by each pixel electrode and the counter electrode.

Here, a conventional alignment control means will be described by taking a vertical alignment type liquid crystal display device having an alignment control window as an example. FIG. 8 is a plan view of a pixel region corresponding to one pixel electrode of a vertical alignment type liquid crystal display device having an alignment control window, and FIG. 9 is a sectional view taken along the line AA ′.

First, the structure of a vertical alignment type liquid crystal display device having an alignment control window will be described with reference to FIG. The TFT 3 covered with the interlayer insulating film 2 is formed on the first substrate 1 for each pixel. A pixel electrode 4 connected to the TFT 3 via a contact hole and a first vertical alignment film 5 are formed on this. On the second substrate 6 arranged so as to face the first substrate 1, a counter electrode 7 common to each pixel and a second electrode
Vertical alignment film 8 is formed. First substrate 1 and second
The liquid crystal 9 is filled between the substrates 6 of the
The alignment of the liquid crystal molecules 10 is controlled according to the electric field strength formed by the voltage applied between the counter electrode 7 and the counter electrode 7.
As a result, the polarization characteristic of the liquid crystal 9 changes, and the transmittance of the light linearly polarized by the polarizing plate (not shown) is controlled. Then, the counter electrode 7 is opened and the alignment control window 31 is formed. For example, the orientation control window 31 is a region having no electrode having a shape in which “Y” characters are connected upside down as shown in FIG.

With this structure, when a voltage is applied to the pixel electrode 4 and the counter electrode 7, electric fields 12 and 13 are formed, and the liquid crystal molecules 10 tilt. At the end of the pixel electrode 4, the electric field 12
Has a shape inclined obliquely from the pixel electrode 4 toward the counter electrode 7. Similarly, since the alignment control window 31 has no electrode, the electric field 13 has a shape inclined from the counter electrode 7 toward the pixel electrode 4. Therefore, the liquid crystal molecule 10 tilts toward the center of the pixel electrode 4 even if there is no pretilt angle.

In the region where the alignment control window 31 is formed, even if a voltage is applied to the pixel electrode 4 and the counter electrode 7, the counter electrode 7 is not present in the alignment control window 31, so that an electric field is not formed and the liquid crystal is formed. The molecule 10 is fixed in the initial orientation state, that is, in the vertical direction. In this way, the alignment direction of the liquid crystal faces the alignment control window 31 due to the continuity of the liquid crystal, and a wider viewing angle than the TN mode horizontal alignment liquid crystal display device can be obtained.

Next, a conventional orientation control window will be described with reference to FIG. An alignment control window 31 is formed in the counter electrode 7 in the pixel region 14 formed by partitioning the first substrate 1 and the second substrate 6 by the pixel electrode 4.
The alignment control window 31 has a long extending portion 31a extending in the vertical direction of the drawing in the center of the pixel region 14, and short extending portions 31b extending from the ends of the long extending portion 31a toward the four corners of the pixel region 14.
It is composed of.

The orientation of the liquid crystal molecules 10 is in the state where a voltage is applied to the pixel electrode 4 and the counter electrode 7, and is indicated by a double circle and an arrow. Since the liquid crystal molecules 10a located immediately below the alignment control window 31 have no electrodes as described above, they are aligned vertically even when a voltage is applied. In contrast,
The liquid crystal molecules 10b, 10c, 10d, and 10e that are not under the alignment control window 31 in the pixel region 14 are aligned to be perpendicular to the generated electric field 12 and electric field 13 when a voltage is applied, and 10b is On the left side of the drawing, 10c is on the right side of the drawing, 10d is on the lower side of the drawing, and 10e is on the upper side of the drawing.

[0009]

The vertical alignment type liquid crystal display device having the above alignment control means has an advantage that it is not necessary to perform rubbing treatment on the vertical alignment film and the manufacturing process can be omitted. . However, in general, such a liquid crystal display device has a weaker force for controlling the alignment direction of the liquid crystal than other liquid crystal display devices which rub the alignment film to control the alignment direction of the liquid crystal.

In addition, as shown in FIG. 8, in the orientation control window 31 in which the "Y" characters are connected upside down, the orientation control window 31
Immediately below a portion (hereinafter, referred to as a “branching region”) 31c where the two branches extend to connect the two short extension portions 31b,
Electric fields in two directions are generated by the two adjacent short extensions 31b. Further, since the liquid crystal molecules 10 driven in different alignment directions by the two electric fields are adjacent to each other, a boundary line is generated in the alignment direction of the liquid crystal molecules 10, and the alignment direction of the liquid crystal molecules 10 is disturbed on the boundary line. I will end up. as a result,
The light leak 15 was generated just below the branch region 31c. Then, the liquid crystal molecules 10a located under the elongated portion 31a are influenced by the electric field generated in the branch region 31c.
Even in a part of the above, the orientation was originally controlled, that is, the orientation was different from the vertical direction.

Therefore, the present invention reduces the disturbance of the alignment direction of the liquid crystal molecules, eliminates the light leakage caused by the disturbance, and improves the display quality of the vertical alignment type liquid crystal display device having the alignment control means. With the goal.

[0012]

The present invention has been made to achieve the above object, and a plurality of gate lines are arranged in a row direction to transmit a gate voltage and a plurality of gate lines are arranged in a column direction to transmit a signal voltage. A drain line, a plurality of auxiliary capacitance lines arranged in the row direction, a switching element arranged at an intersection of the gate line and the drain line, and a pixel connected to the drain line via the switching element. A first substrate having an electrode,
A second substrate facing the first substrate and having a counter electrode forming a capacitance together with the pixel electrode; and a liquid crystal having a negative dielectric anisotropy between the first and second substrates. A vertical alignment type liquid crystal display device having a vertical alignment film for vertically aligning the liquid crystal in an initial alignment state in which no voltage is applied, having alignment control means formed corresponding to each of the pixel electrodes, The orientation control means includes a long extending portion extending in the column direction and a short extending portion extending from an end of the long extending portion and forming a predetermined angle with the long extending portion, and one end of each of the long extending portions is provided. A vertical alignment type liquid crystal display device having a short extension.

Further, the alignment control means is the above-described vertical alignment type liquid crystal display device which is an alignment control window formed by opening the counter electrode.

Alternatively, in the above-described vertical alignment type liquid crystal display device, the alignment control means is an alignment control tilted portion formed by providing a protrusion or a depression in a region of the vertical alignment film corresponding to each of the pixel electrodes. is there.

Further, a pixel region formed by partitioning the first and second substrates by the pixel electrode is rectangular, and a short extension of the alignment control means is formed on a longer opposite side of the pixel region. Is the above-described vertical alignment type liquid crystal display device which is formed so as to extend in the direction of one end point on each of the opposite sides.

Further, in the above vertical alignment type liquid crystal display device, the short extending portion is formed on the same side with the extension line of the long extending portion as a boundary.

Alternatively, in the above vertical alignment type liquid crystal display device, the short extending portions are formed on different sides with an extension line of the long extending portion as a boundary.

Further, the alignment control means corresponds to the pixel electrodes adjacent to each other in the column direction, and is the above-mentioned vertical alignment type liquid crystal display device which is continuously formed.

Further, it is made of a light-shielding conductor,
In the vertical alignment type liquid crystal display device, the wiring formed in the column direction is formed so as to overlap the alignment control means.

Further, in the above-mentioned vertical alignment type liquid crystal display device, the wiring is the drain line.

Alternatively, the vertical alignment type liquid crystal display device is
A plurality of auxiliary capacitors that hold the signal voltage together with the pixel electrode and an auxiliary capacitor line that is formed in a row direction and connects the auxiliary capacitors are provided, and the wiring electrically connects the plurality of auxiliary capacitor lines. The above-mentioned vertical alignment type liquid crystal display device is a storage capacitor connecting line.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described.
The alignment control means that divides the alignment direction of the liquid crystal for each pixel electrode that drives the liquid crystal includes an alignment control window that is formed by opening a counter electrode that faces the pixel electrode and drives the liquid crystal together with the pixel electrode. There are alignment control tilted portions formed by providing a ridge on either the pixel electrode or the counter electrode, and a combination of the alignment control window and the alignment control tilted portion. By dividing the electric field formed by the counter electrodes, the alignment direction of the liquid crystal in each pixel electrode is divided.

Hereinafter, in each of the embodiments, a vertical alignment type liquid crystal display device having an alignment control window will be described as an example.
The present invention can be applied not only to the orientation control window, but also to the above orientation control inclined portion.

First, the orientation control means according to the first embodiment will be described. FIG. 1 is a plan view of a pixel region corresponding to one pixel electrode of a vertical alignment type liquid crystal display device having an alignment control window, and FIG. 2 is a sectional view taken along line AA ′.

First, the structure of the vertical alignment type liquid crystal display device having the alignment control window of this embodiment will be described with reference to FIG. A TFT covered with an interlayer insulating film 2 on the first substrate 1.
3 is formed for each pixel. A pixel electrode 4 connected to the TFT 3 via a contact hole and a first vertical alignment film 5 are formed on this. A counter electrode 7 common to each pixel and a second vertical alignment film 8 are formed on a second substrate 6 arranged so as to face the first substrate 1. First
The liquid crystal 9 is filled between the substrate 1 and the second substrate 6, and the alignment of the liquid crystal molecules 10 is performed according to the intensity of the electric field formed by the voltage applied between the pixel electrode 4 and the counter electrode 7. Is controlled. As a result, the polarization characteristic of the liquid crystal 9 changes, and the transmittance of the light linearly polarized by the polarizing plate (not shown) is controlled. Then, the counter electrode 7 is opened and the alignment control window 11 is formed.

In this structure, when a voltage is applied to the pixel electrode 4 and the counter electrode 7, electric fields 12 and 13 are formed and the liquid crystal molecules 10 are tilted. At the end of the pixel electrode 4, the electric field 12
Has a shape inclined obliquely from the pixel electrode 4 toward the counter electrode 7. Similarly, since the alignment control window 11 has no electrode, the electric field 13 has a shape inclined from the counter electrode 7 toward the pixel electrode 4. Therefore, the liquid crystal molecule 10 tilts toward the center of the pixel electrode 4 even if there is no pretilt angle.
Further, in the region where the alignment control window 11 is formed, even if a voltage is applied to the pixel electrode 4 and the counter electrode 7, the alignment control window 1
Since there is no counter electrode 7 in 1, the electric field is not formed, and the liquid crystal molecules 10 maintain the initial alignment state, that is, the alignment in the vertical direction. In this way, the alignment control window 1 is formed by the continuity of the liquid crystal.
The alignment directions of the liquid crystal molecules 10 of No. 1 face each other, and the alignment directions of the liquid crystal molecules 10 on each pixel electrode 4 can be divided.

Next, the orientation control window of the present embodiment will be described with reference to FIG. A pixel region 1 formed by partitioning the first substrate 1 and the second substrate 6 by the pixel electrode 4.
Corresponding to No. 4, the alignment control window 11 is formed in the counter electrode 7. The alignment control window 11 has a long extending portion 11 a extending in the vertical direction of the drawing and a long extending portion 11 a in the center of the pixel region 14.
It is constituted by a short extension portion 11b which is bent and extends from the both ends to the same side with the extension line of the long extension portion 11a as a boundary.

In the present embodiment, the orientation control window 11 has a long extension 11a parallel to the long side of the pixel region 14 and a long extension 1.
It is characterized in that it is formed in a continuous line shape without branching, which is composed of short extending portions 11b extending from both ends of 1a. Further, in the present embodiment, the long extension 11a is bent to the same side with the extension line as a boundary. This embodiment is different from the conventional one in that a branch area 31c as shown in FIG.
Is the point that does not exist. With this configuration, it is possible to eliminate the disorder of the alignment of the liquid crystal molecules that has occurred in the conventional alignment control window immediately below the branch region, and prevent the occurrence of light leakage due to this.

The orientation of the liquid crystal molecules 10 is in a state where a voltage is applied to the pixel electrode 4 and the counter electrode 7, and is indicated by a double circle and an arrow. Since the liquid crystal molecules 10a located directly below the alignment control window 11 have no electrodes as described above, they are aligned vertically even when a voltage is applied. Further, since the electric field generated in the bending region 11c is weaker than the electric field generated in the conventional branching region, the liquid crystal molecules 10a immediately below the bending region 11c are also aligned in a substantially vertical direction. On the other hand, the liquid crystal molecules 10b, 10c, 10d and 10e which are not under the alignment control window 11 in the pixel region 14 are aligned so as to be perpendicular to the generated electric field 12 and electric field 13 when a voltage is applied. The liquid crystal molecule 10b is on the left side of the drawing.
The liquid crystal molecules 10c face the right side of the drawing, and the liquid crystal molecules 10d and the liquid crystal molecules 10e face the ends of the short extending portions 11b.

Here, a remarkable feature of the present invention is that, in the present embodiment, the conventional orientation control window in which one end portion of the long extension portion is branched to form two short extension portions in FIG. Three
This means that the disclination line 16 is generated at a fixed position in the area where the other short extension 31b of 1 existed, although the short extension of the orientation control window did not exist. This is because a liquid crystal molecule aligned in the row direction and a liquid crystal molecule aligned in the column direction are adjacent to each other due to an electric field generated by the end portion of the pixel electrode 4, so that a boundary line is formed in the alignment direction of the liquid crystal molecule 10. This is because it has occurred. This is because the disclination 16 does not appear if the alignment control window 11 is formed into a simple linear shape with only the long extending portions 11a. It was necessary to control. In the disclination line 16 in FIG. 1, the boundary line in the alignment direction of the liquid crystal molecules 10 is visually recognized, and the conventional alignment control window 31 shown in FIG.
Compared to the other short extension 31b, it is extremely fine, and its position is almost pixel by pixel due to the alignment control window 11, in particular the alignment control of the liquid crystal by the short extension 11b and the continuity of liquid crystal alignment. There is no difference.

Further, in the alignment control window of this embodiment, the short extension is halved as compared with the conventional alignment control window, and the alignment of the liquid crystal molecules can be divided in a narrower area in each pixel region. The aperture ratio of the pixel can be improved.

Next, the orientation control means according to the second embodiment will be described. In the first embodiment,
The short extending portions were extended one by one from both ends of the long extending portion on the same side with the extension line of the long extending portion as a boundary, but in the present invention, the short extending portions are extended one by one from both ends of the long extending portion. May extend on different sides with the extension line of as a boundary.

FIGS. 3A and 3B are plan views of a pixel region corresponding to one pixel electrode of a vertical alignment type liquid crystal display device having an alignment control window according to the second embodiment. The cross-sectional view taken along the line AA ′ is similar to that of the first embodiment, and is therefore omitted, and the alignment control window 11 of FIG.
It should be read as 1.

Next, the orientation control window of this embodiment will be described with reference to FIGS. 3 (a) and 3 (b). An alignment control window 21 is formed in the counter electrode 7 in the pixel region 14 formed by partitioning the first substrate 1 and the second substrate 6 by the pixel electrode 4. The orientation control window 21 is provided in the pixel area 1
At the center of 4, a long extending portion 21a extending long in the vertical direction of the drawing
And a short extending portion 21b that is bent and extends from both ends of the long extending portion 21a to different sides with the extension lines of the long extending portion 21a as boundaries.

In this embodiment, as in the first embodiment, the alignment control window 21 has a long extension 21a parallel to the long side of the pixel region 14 and a short extension 21b extending from both ends of the long extension 21a. It is formed in a continuous line shape with no branch and is not formed with the branch region 31c as shown in FIG. However, in the present embodiment, unlike the first embodiment, the short extension portion 21b is bent to different sides with the extension line of the long extension portion 21a as a boundary. With this configuration, it is possible to eliminate the disturbance in the alignment of the liquid crystal molecules that has occurred immediately below the branch region, and prevent the occurrence of light leakage due to this.

The orientation of the liquid crystal molecules 10 is in a state where a voltage is applied to the pixel electrode 4 and the counter electrode 7, and is indicated by a double circle and an arrow. Since the liquid crystal molecules 10a located directly below the alignment control window 21 have no electrodes as described above, they are aligned vertically even when a voltage is applied. Further, since the electric field generated in the bending region 21c is weaker than the electric field generated in the conventional branching region, the liquid crystal molecules 10a immediately below the bending region 21c are also aligned in a substantially vertical direction. On the other hand, in the pixel region 14, the liquid crystal molecules 10b, 10c, 10d, and 10e not under the alignment control window 21 are aligned so as to be perpendicular to the generated electric field 12 and electric field 13 when a voltage is applied. The liquid crystal molecule 10b is on the left side of the drawing.
The liquid crystal molecules 10c face the right side of the drawing, and the liquid crystal molecules 10d and the liquid crystal molecules 10e face the ends of the short extending portions 21b.

Here, in the present embodiment, as in the first embodiment, in the conventional orientation control window 31 shown in FIG. 8, one end of the long extended portion is branched to form two short extended portions. In the region where the other short extension 31b of the above was present, although the short extension of the alignment control window does not exist, the position is fixed.
Disclination line 16 is generated. The disclination line 16 in FIG.
The boundary line in the alignment direction of is visually recognized and is extremely fine compared to the other short extension 31b of the conventional alignment control window 31 shown in FIG. It is similar to the first embodiment that the position of the liquid crystal hardly changes from pixel to pixel due to the alignment control of the liquid crystal by the short extension 21b and the continuity of the liquid crystal alignment.

Also, in the alignment control window of this embodiment, the short extension portion is halved as compared with the conventional alignment control window as in the first embodiment, and the alignment of liquid crystal molecules is divided into smaller areas in each pixel region. Therefore, the aperture ratio of the pixel can be improved.

Next, a third embodiment will be described.
In the first and second embodiments, the alignment control window formed in the pixel region corresponding to one pixel electrode of the counter electrode has been shown. Furthermore, one alignment control window that is long in the column direction may be formed corresponding to a plurality of pixel regions that are continuous in the column direction. FIG. 4 is a plan view of a counter electrode having an alignment control window according to the third embodiment.

Focusing on one pixel area 14, the alignment control window 11 of the present embodiment is extended in the short extension portion 11b of the alignment control window 11 shown in FIG. The pixel region 14 is continuous with the short extension 11b. By repeating this, the orientation control window 11 is formed in a linear shape in the column direction. By eliminating the end EG of the short extension of the alignment control window 11 shown in FIG. 1, it is possible to eliminate the influence on the liquid crystal alignment caused by the electric field generated by the end EG.

On the other hand, as shown by the dotted line, the disclination line 16 shown in FIG. 1 is also formed,
Since the disclination line 16 itself is thin and its position is aligned with all pixels by the orientation control window 11, even when used as a display device, problems such as display unevenness and flicker do not occur.

The characteristic point of this embodiment is that the orientation control window 1
1 is a plurality of pixel regions 1 in which the counter electrodes 7 are continuous in the column direction.
4 is formed as an alignment control window that is long in the column direction and is open corresponding to No. 4, and there is no end EG of the short extension 11b of the alignment control window 11 in each pixel region 14. Thereby, the electric field formed by the end portion EG of the short extension 11b of the alignment control window 11 can be eliminated, and alignment control of the liquid crystal molecules 10 can be made more accurate and easy.

In this embodiment, the alignment control window may be formed as a long alignment control window in the column direction by opening the counter electrode corresponding to a plurality of pixel regions continuous in the column direction. In FIG. 5, the pixel regions 14 of FIGS. 3A and 3B are connected alternately in the column direction, and the pixel regions 14 are opened to correspond to the plurality of pixel regions 14 continuous in the column direction. FIG. 6 is a plan view of a counter electrode having a long alignment control window.
Similar to FIG. 4, the orientation control window 21 is shown by a solid line and the disclination line 16 is shown by a dotted line. Although the disclination line 16 itself is thin, if the position and shape of the disclination line 16 are different in the adjacent pixel regions 14, it causes a problem such as display unevenness and flicker when used as a display device. It is better to have 14 items. Therefore, in FIG. 5, the alignment control windows 21 of the pixel regions 14 adjacent to each other in the row direction have the same shape.

Next, a fourth embodiment will be described.
FIG. 6 is a plan view of the pixel region and the wiring according to the present invention, and particularly, FIGS. 6B and 6D are plan views of the pixel region and the wiring according to the fourth embodiment.

First, FIG. 6A shows a pixel region and wiring having the alignment control window of FIG. The gate line 31 and the auxiliary capacitance line 32 extend in the row direction. The drain line 33 extends in the column direction.
The pixel electrode 4 is arranged so as to be surrounded by the gate line 31 and the drain line 33, and the alignment control window 1 is provided in the counter electrode 7 (not shown) corresponding to the pixel electrode 4.
1 is formed.

The gate line 31 transmits a gate voltage to the gate electrode 3g forming the TFT 3. The auxiliary capacitance line 32 forms an auxiliary capacitance 34 together with the semiconductor layer 3s forming the TFT 3. The drain line 33 is T
A signal voltage is transmitted to the pixel electrode 4 via the FT3.

Normally, the drain line 3 extending in the column direction
Since 3 is formed of a low resistance metal such as Al (aluminum), it has a light shielding property. On the other hand, since the liquid crystal molecules 10 immediately below the alignment control window 11 maintain the initial alignment state, that is, the vertical alignment even when a voltage is applied to the pixel electrode 4 and the counter electrode 7, the region where the alignment control window 11 is formed is It is always shielded from light. Therefore, in the display region of the vertical alignment type liquid crystal display device having the configuration shown in FIG.
There will be a portion shielded by 3 and a portion shielded by the alignment control window 11.

Therefore, as shown in FIG. 6B, the drain line 33 is arranged so as to overlap the alignment control window 11.
Compared with FIG. 6A, a part of the portion shielded by the drain line 33 in FIG. 6A is reduced, and the aperture ratio is improved.

Further, as shown in FIG. 6C, a plurality of auxiliary capacitance lines 32 are connected by an auxiliary capacitance connecting line 35 to increase the capacitance, so that the drain line 33, the gate line 31, and the auxiliary capacitance line 32 are connected. It has been devised to absorb the change in voltage of the auxiliary capacitance 34 due to the capacitive coupling that occurs at the crossing point of, and eliminate the unevenness of the image. Normally, the auxiliary capacitance line 32 is parallel to the gate line 31,
That is, since it extends in the row direction, the auxiliary capacitance connecting line 35 connecting the plurality of auxiliary capacitance lines 32 is formed in the column direction. Further, since the auxiliary capacitance connecting line 35 connects the auxiliary capacitance line 32 via a contact having a high resistance, it is desirable that the auxiliary capacitance connecting line 35 is formed of a metal having a low resistance. It is often formed in the same layer as the line 33. Therefore, FIG.
The aperture ratio can also be improved by forming the auxiliary capacitance coupling line 35 so as to overlap the orientation control window 21 as shown in (d).

The characteristic point of this embodiment is that the orientation control window 1
1 and wirings such as the drain line 33 and the auxiliary capacitance coupling line 35, which extend in the column direction and have a light shielding property, are arranged so as to overlap each other. Since the liquid crystal molecules 10 immediately below the alignment control window 11 maintain the initial alignment state, that is, vertical alignment even when a voltage is applied to the pixel electrode 4 and the counter electrode 7,
The region where the orientation control window 11 is formed is always shielded from light. The vertical alignment type liquid crystal display device is made of a light-shielding conductor and has wirings extending in the column direction.
Therefore, by forming this wiring so as to overlap with the alignment control window, it is possible to reduce the light-shielded portion in the pixel region and improve the aperture ratio.

Further, although not shown here, the alignment electrodes of the third embodiment are formed so that the counter electrodes are opened corresponding to the plurality of pixel regions 14 continuous in the column direction, and are formed as alignment control windows long in the column direction. When the control window and the wiring of the present embodiment which extends in the column direction and has a light blocking property are overlapped, the alignment control window is formed in a linear shape, so that the shape and the position of the wiring can be substantially matched. it can. Therefore, the aperture ratio can be further improved.

Although the orientation control window has been illustrated as the orientation control means in each embodiment, the present invention can be applied to the case where the orientation control means is the orientation control inclined portion.
FIG. 7 is a cross-sectional view of a vertical alignment type liquid crystal display device having an alignment control inclination part.

An interlayer insulating film 102 is formed on the first substrate 101.
The TFT 103 covered with is formed for each pixel.
A pixel electrode 104 connected to the TFT 103 via a contact hole, and a first vertical alignment film 105 are formed on this. On the second substrate 106 arranged so as to face the first substrate 101, a counter electrode 107 common to each pixel is provided.
Then, the second vertical alignment film 108 is formed. The liquid crystal 109 is filled between the first substrate 101 and the second substrate 106, and the alignment of the liquid crystal molecules 110 is performed in accordance with the electric field strength generated by the voltage applied between the pixel electrode 104 and the counter electrode 107. Is controlled. As a result, the polarization characteristic of the liquid crystal 109 changes, and the transmittance of the light linearly polarized by the polarizing plate (not shown) is controlled. Then, a raised portion LB made of an insulating film is formed on the counter electrode 107,
The orientation control inclined portion 111 is formed. This ridge L
B is raised with respect to the plane occupying most of the counter electrode 107.

With this structure, when a voltage is applied to the pixel electrode 104 and the counter electrode 107, electric fields 112 and 113 are formed and the liquid crystal molecules 110 are tilted. At the end of the pixel electrode 104, the electric field 112 is transmitted from the pixel electrode 104 to the counter electrode 1.
The shape is inclined obliquely toward 07. Similarly, since the protrusion LB is formed in the orientation control inclined portion 111 by the insulating film and is electrically insulated, the electric field 113 has a shape inclined from the counter electrode 107 toward the pixel electrode 104. Therefore, the liquid crystal molecules 110 tilt toward the center of the pixel electrode 104 even if there is no pretilt angle. Further, in the region where the orientation control control sloped portion 111 is formed,
Since the protrusion LB made of the insulating film is formed on the orientation control inclined portion 111, the pixel electrode 104 and the counter electrode 10 are formed.
An electric field is not formed even if a voltage is applied to 7, and liquid crystal molecules 11
0 is fixed in the initial alignment state, that is, in the vertical direction. In this way, the alignment direction of the liquid crystal molecules 110 is opposed to the alignment control tilted portion 111 due to the continuity of the liquid crystal, and
It is possible to divide the alignment direction of the liquid crystal molecules 110 on the No. 4 screen.

The sectional views of the orientation control means shown in each of the embodiments and the drawings are examples, and the present invention is not limited to this. Further, in each of the embodiments, the orientation control window has been illustrated as the orientation control means, but the present invention is not limited to the orientation control window, and even if the orientation control means is the orientation control tilting portion, the orientation control window and the orientation control tilting portion. A combination of and can also be applied.

[0056]

According to the vertical alignment type liquid crystal display device of the present invention, a plurality of gate lines are arranged in a row direction to transmit a gate voltage, a plurality of gate lines are arranged in a column direction to form a drain line for transmitting a signal voltage, and a row direction. A first substrate having a plurality of auxiliary capacitance lines, a switching element arranged corresponding to the intersection of the gate line and the drain line, and a pixel electrode connected to the drain line via the switching element; A second substrate facing the first substrate and having a counter electrode that forms a capacitance together with the pixel electrode, and a liquid crystal having a negative dielectric anisotropy between the first and second substrates and a voltage A vertical alignment film that vertically aligns liquid crystal in an initial alignment state in which no voltage is applied, and alignment control means formed corresponding to each pixel electrode, and the alignment control means extends in the column direction. The orientation control means is branched by the extension part and the short extension part extending from the end of the long extension part and forming a predetermined angle with the long extension part, and each end part of the long extension part has one short extension part. Therefore, it is possible to eliminate the portion that does not exist, and it is possible to eliminate the variation in the alignment direction of the liquid crystal caused by the influence of the electric fields in the two directions generated in the branched portion and the light leakage caused by the variation. Moreover, since the area of the orientation control means can be reduced, the aperture ratio is improved.

The above-mentioned alignment control means has an alignment control window formed by opening a counter electrode, and an alignment control inclined portion formed by providing a vertical alignment film with protrusions or depressions. A liquid crystal display device with a wide viewing angle can be provided by dividing the electric field in each region and dividing the alignment direction of the liquid crystal.

Further, in the vertical alignment type liquid crystal display device of the present invention, the pixel region formed by partitioning the first and second substrates by the pixel electrode is rectangular, and the longer opposite side of the pixel region is The short extension portion of the orientation control means is formed so as to extend only in the direction of one end point on each side of the opposite side, so that the branch portion of the orientation control means can be eliminated, and the branch portion can be generated. It is possible to eliminate the variation in the alignment direction of the liquid crystal caused by the influence of the electric fields in the two directions and the light leakage caused by the variation. Moreover, since the area of the orientation control means can be reduced, the aperture ratio is improved.

Further, in the vertical alignment type liquid crystal display device of the present invention, even if the short extension is formed on the same side with the extension line of the long extension as a boundary, it is formed on the different side with the extension line of the long extension as a boundary. It does not matter. Both short extensions can eliminate the branching portion of the orientation control means,
Since it is possible to eliminate the variation in the alignment direction of the liquid crystal caused by the influence of the electric fields in the two directions generated in the branched portion and the leakage of light caused thereby, it is possible to reduce the area of the alignment control means. , The aperture ratio is improved.

Further, in the vertical alignment type liquid crystal display device of the present invention, the alignment control means is formed continuously corresponding to the pixel electrodes adjacent in the column direction, whereby the edge of the short extension part of the alignment control means is formed. It is possible to prevent an electric field from being generated by the portion and more accurately and easily control the alignment direction of the liquid crystal in the pixel region.

Furthermore, in the vertical alignment type liquid crystal display device of the present invention, since the wirings made of a light-shielding conductor and formed in the column direction are formed so as to overlap the alignment control means, By overlapping the alignment control window having a light-shielding property and the wiring made of a conductor, the light-shielded portion is reduced and the aperture ratio is improved. As the wiring, for example, a drain line can be given. In addition, the vertical alignment type liquid crystal display device of the present invention includes an auxiliary capacitor that holds a signal voltage together with a pixel electrode, an auxiliary capacitor line that is formed in a plurality in the row direction and that connects the auxiliary capacitors, and a plurality of the auxiliary capacitor lines. In the case where the auxiliary capacitance connecting line that is to be electrically connected is provided, even if the auxiliary capacitance connecting line is applied to the wiring, the light-shielded portion is reduced and the aperture ratio is improved.

[Brief description of drawings]

FIG. 1 is a plan view of a pixel region in a vertical alignment type liquid crystal display device according to a first embodiment.

FIG. 2 is a cross-sectional view taken along the line AA ′ of the pixel region in the vertical alignment type liquid crystal display device of the present invention.

FIG. 3 is a plan view of a pixel region in a vertical alignment type liquid crystal display device of a second embodiment.

FIG. 4 is a plan view of a counter electrode in a vertical alignment type liquid crystal display device according to a third embodiment.

FIG. 5 is a plan view of a counter electrode in a vertical alignment type liquid crystal display device according to a third embodiment.

FIG. 6 is a plan view of a pixel region and a wiring in a vertical alignment type liquid crystal display device of a fourth embodiment.

FIG. 7 is a cross-sectional view of a vertical alignment type liquid crystal display device having an alignment control tilt part.

FIG. 8 is a plan view of a pixel region in a conventional vertical alignment type liquid crystal display device.

FIG. 9 is a cross-sectional view taken along the line AA ′ of the pixel region in the conventional vertical alignment type liquid crystal display device. 1, 101: first substrate 2, 102: interlayer insulating film 3, 103: TFT 4, 104: pixel electrode 5, 105: first alignment film 6, 106: second substrate 7, 107: counter electrode 8 , 108: second alignment films 9, 109: liquid crystals 10, 110: liquid crystal molecules 11, 21, 31, 31: alignment control windows 11a, 21a, 31a: long extended portions 11b, 21b, 31b: short extended portions 12, 112: electric field 13, 113: Electric field 14: Pixel region 15: Light leakage 111: Orientation control inclined portion 16: Disclination line EG: End portion LB of short extension portion: Raised portion

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2H090 HC05 HC18 HC20 HD14 JB02                       KA18 LA01 LA04 MA01 MA07                       MA14                 2H092 GA13 GA17 GA20 GA26 JA24                       JA42 JA46 JB13 JB38 JB63                       JB69 KA05 KB14 MA07 MA13                       MA17 MA35 MA37 PA02 QA18                 5C094 AA03 BA03 BA43 CA19 EA04                       EA07 FB16

Claims (10)

[Claims] 1. A plurality of gate lines arranged in a row direction for transmitting a gate voltage, a plurality of gate lines arranged in a column direction for transmitting a signal voltage, a plurality of auxiliary capacitance lines arranged in a row direction, and A first substrate having a switching element arranged corresponding to an intersection of the gate line and the drain line, and a pixel electrode connected to the drain line through the switching element, and facing the first substrate. , A second substrate having a counter electrode that forms a capacitance together with the pixel electrode, a liquid crystal having a negative dielectric anisotropy between the first and second substrates, and an initial stage where no voltage is applied. A vertical alignment type liquid crystal display device having a vertical alignment film for vertically aligning the liquid crystal in an alignment state, having alignment control means formed corresponding to each of the pixel electrodes, The orientation control means comprises a long extending portion extending in the column direction and a short extending portion extending from an end portion of the long extending portion and forming a predetermined angle with the long extending portion, and both end portions of the long extending portion are each one. A vertical alignment type liquid crystal display device having a short extension. 2. The vertical alignment type liquid crystal display device according to claim 1, wherein the alignment control means is an alignment control window formed by opening the counter electrode. 3. The alignment control means is an alignment control sloped portion formed by providing a protrusion or a depression in a region of the vertical alignment film corresponding to each of the pixel electrodes. The vertical alignment type liquid crystal display device described. 4. The first and second pixel electrodes are formed by the pixel electrode.
The pixel area formed by partitioning the substrate is rectangular,
The short extension part of the alignment control means is formed so as to extend only in the direction of one end point on each side of the opposite side on the longer opposite side of the pixel region. 4. The vertical alignment type liquid crystal display device according to any one of 3 above. 5. The short extension portion is formed on the same side with an extension line of the long extension portion as a boundary.
5. The vertical alignment type liquid crystal display device according to claim 4. 6. The vertical alignment type liquid crystal display according to claim 1, wherein the short extensions are formed on different sides with an extension line of the long extensions as a boundary. apparatus. 7. The vertical alignment type liquid crystal according to claim 1, wherein the alignment control unit is formed continuously corresponding to the pixel electrodes adjacent to each other in the column direction. Display device. 8. The wiring according to claim 1, wherein a wiring made of a light-shielding conductor and formed in the column direction is formed so as to overlap the alignment control means. The vertical alignment type liquid crystal display device according to item 1. 9. The vertical alignment type liquid crystal display device according to claim 8, wherein the wiring is the drain line. 10. The vertical alignment type liquid crystal display device includes an auxiliary capacitance that holds the signal voltage together with the pixel electrode, and a plurality of auxiliary capacitance lines that are formed in a row direction and that connect the auxiliary capacitances. 9. The vertical alignment type liquid crystal display device according to claim 8, wherein the wiring is a storage capacitor connecting line that electrically connects the plurality of storage capacitor lines.